1. Melt the 2 tablespoons butter in a saute pan over LOW-MEDIUM heat.
2. Add the flour, salt, and pepper. Cook for a few minutes, whisking together to make a bloud roux.
3. Gradually add the cream. Keep whisking the mixture to avoid lumps. Simmer this bechamel sauce until it's reduced to about 1 cup. Remove from heat and let cool.
4. Carefully pick through the crabmeat and make sure there are no bits of shell. Add the crabmeat to the bechamel sauce.
5. Melt 1 tablespoon of butter in another small pan and saute the onions until translucent.
6. Place Ritz crackers in a small plastic bag, zip close (removing all air), and then crush into crumbs with your hands or a rolling pin.
7. Add the onions to the sauce, then stir in cracker crumbs. Mix well. Texture should hold together to form a cake, but still be slightly moist. If necessary, add more cracker crumbs. then set aside to cool. If desired, you can prepare this mixture in advance - it will keep for several days in the fridge.
8. When the mixture has cooled, form into cakes. Then coat with breadcrumbs.
9. Add olive oil to a large saute pan over MEDIUM-HIGH heat. Once the oil is hot, add the crab cakes. Cook two minutes on both sides, or until the crab cakes slightly brown and form a nice crust.